A trailer, fifth wheel, or other non-powered wheeled structure may be towed behind a vehicle using a trailer hitch assembly. While trailer hitch assemblies come in various configurations, a typical configuration includes a trailer coupler and a hitch ball. The trailer coupler, which is connected to the trailer, includes a trailer tongue that extends from the trailer. A cup of the trailer tongue is positioned around a hitch ball, which in turn is connected to the tow vehicle. The trailer coupler locks into place via a lever and retaining pin. A properly hitched trailer forms a single structural unit with the tow vehicle that is able to negotiate turns while remaining stable on a roadway. However, because the hitch ball is located at the rear end of the tow vehicle, it may be difficult for an operator to properly align the hitch ball and the trailer coupler during a hitching operation, particularly in low lighting conditions.
Modern vehicles include one or more cameras that provide back-up assistance. Rear camera systems used for back-up assistance may employ visual overlay graphics that are superimposed on a camera image to provide back-up steering guidance. Camera images and vehicle coordinates in such operations are related via a calibration process that determines camera parameters, e.g., focal length, optical center, orientation, and position. Camera modeling techniques may be used which help account for the height of the trailer tongue above ground level, while also modeling the motion of the tow vehicle with respect to a center of rotation while an operator steers the vehicle. However, camera-based techniques for guiding back-up operations may be less than optimal when applied to a trailer hitching operation, particularly during close-up control phases of the trailer hitching operation.